title: Lung size mismatch and survival after single and bilateral lung transplantation.
abstract: BACKGROUND
  A higher predicted total lung capacity (pTLC)-ratio (=pTLC donor/pTLC recipient), suggestive of oversized allografts, is associated with improved survival after lung transplantation. It is unknown whether the pTLC-ratio has a different association with survival in bilateral (BLT) versus single lung transplantation (SLT).
  
  
  METHODS
  The pTLC-ratio was calculated for all adult patients in the United Network of Organ Sharing lung transplant (LTx) registry who underwent first-time LTx in the post lung allocation score era, between May 2005 and April 2010. The LTx recipients were stratified according to procedure (BLT vs SLT). Risk of death at 1 year after LTx was analyzed using Kaplan-Meier survival and Cox proportional hazards models.
  
  
  RESULTS
  In the 4,520 BLT patients, each 0.1 increase in pTLC-ratio conferred a 7% decrease in the hazard for death at 1 year (p < 0.001) in univariate analysis. This association remained significant after controlling for diagnosis, comorbidities, acuity, donor, and transplant factors (hazard ratio [HR] 0.93, 95% confidence interval [CI] 0.88 to 0.98, p = 0.01). Additional adjustment by a propensity score to account for biases to oversizing showed similar results (HR 0.94, 95% CI 0.90 to 0.99, p = 0.018). In the 2,477 SLT patients, each 0.1 increase in pTLC-ratio conveyed a 6% decrease in the hazard for death at 1 year (p = 0.002) in univariate analysis, which did not persist in the multivariate model (HR 1.00, p = 0.8).
  
  
  CONCLUSIONS
  A higher pTLC-ratio, suggestive of an oversized allograft, is associated with improved survival after lung transplantation. This association is primarily evident in BLT patients.
authors.affiliation: Lung Transplant Program, Division of Pulmonary, Critical Care and Occupational Medicine, University of Iowa Hospitals and Clinics, 200 Hawkins Dr, C 33 GH, Iowa City, IA 52242, USA. michael-eberlein@uiowa.edu
authors.forename: Michael
authors.initials: M
authors.lastname: Eberlein
authors.forename: Robert M
authors.initials: RM
authors.lastname: Reed
authors.forename: Servet
authors.initials: S
authors.lastname: Bolukbas
authors.forename: Kalpaj R
authors.initials: KR
authors.lastname: Parekh
authors.forename: George J
authors.initials: GJ
authors.lastname: Arnaoutakis
authors.forename: Jonathan B
authors.initials: JB
authors.lastname: Orens
authors.forename: Roy G
authors.initials: RG
authors.lastname: Brower
authors.forename: Ashish S
authors.initials: AS
authors.lastname: Shah
authors.forename: Lawrence
authors.initials: L
authors.lastname: Hunsicker
authors.forename: Christian A
authors.initials: CA
authors.lastname: Merlo
mesh_terms: D000328:Adult; D046148:Donor Selection; D006801:Humans; D016040:Lung Transplantation / Q000379:methods* / Q000401:mortality*; D008875:Middle Aged; D009929:Organ Size; D018579:Patient Selection; D015996:Survival Rate
keywords: 12